CN100403850C - Circularly Polarized Wave Positioning Method Applicable to TD-SCDMA Network - Google Patents

Abstract

The invention provides an indoor positioning method based on an electromagnetic wave polarization technology, and relates to a wireless positioning technology. According to the invention, a small number of transmitting points are laid indoors, circularly polarized electromagnetic waves are uniformly transmitted to the indoor space, and the mobile phone or other mobile terminals only receive the energy of the direct signals of the transmitting points by additionally arranging the matched polarized antenna, so that most of the energy of reflected signals is shielded, and the influence of dynamic environments such as people flow is effectively inhibited; the energy of direct signals received everywhere in a room is utilized to establish a signal intensity database, and accurate indoor positioning is realized in a coverage area under the condition that the signals of 3 transmitting points can be received. The system can be used by users only needing indoor positioning service independently, and can also realize real seamless positioning by combining an outdoor positioning technology based on other wireless communication networks.

Description

Circularly Polarized Wave Positioning Method Applicable to TD-SCDMA Network

technical field

The invention relates to the technical field of wireless communication, in particular to the wireless positioning technology utilizing the polarization properties of electromagnetic waves.

Background technique

At present, the widely used GPS positioning technology cannot be applied indoors because the satellite signal is not received or the satellite signal is too weak. The technologies such as CELL-ID and TDOA that can be adopted for indoor positioning cannot meet the needs of users due to the low positioning accuracy. When the positioning method based on wireless local area network is implemented, a large number of third-party devices need to be installed, and the cost of installation and maintenance is very expensive. Moreover, the technical environment has a great impact, and the system performance is very unstable, which seriously affects the further improvement of positioning accuracy.

Contents of the invention

The present invention proposes a circularly polarized wave indoor positioning method: laying a circularly polarized wave transmitting point indoors, a polarized antenna receives the signal of the transmitting point, and utilizes the signal strength for positioning. Therefore, the influence of environmental change factors is reduced, and at the same time, the cost of system installation and maintenance is small and the positioning stability is high.

The technical solution of the present invention is: the location server integrates the spatial database, the signal strength database, the communication function module, the calculation module and the data feedback module; wave, the polarized antenna installed on the mobile terminal or the auxiliary equipment connected to the mobile terminal receives the signal strength of the circularly polarized wave at the even number of reflections and sends it to the signal strength database; the system initializes the signal strength, according to the required Positioning accuracy Divide the indoor space into several grids, measure the signal strength of the corresponding transmission point in the center of the grid, and input it into the signal strength database; when the mobile terminal receives signals reflected by 3 or more transmission points, the user terminal sends The positioning request is sent to the LBS; the LBS instructs the user terminal to send the circularly polarized waves of at least 3 transmitting points and their reference points to the location server; the location server uses the circularly polarized wave signal strength of the ground reference point to determine the After the wave signal is corrected for power, use methods such as maximum likelihood matching to query the signal strength database to obtain several sets of approximate matching data; the calculation module calls the matching data to calculate the location information of the user terminal, and obtains the positioning result, and the data feedback module feeds back the result to user. When using the positioning service in other communication networks (such as TD-SCDMA), the user sends a positioning request on the auxiliary device; the information of the launch point and the reference point is transmitted to the mobile terminal through the auxiliary device, and the above information is transmitted by the core network to the location server. The polarized antenna can be installed on the mobile terminal or an auxiliary device connected to the mobile terminal.

The beneficial effects of the present invention are: the circular polarization positioning system is used to realize precise positioning of indoor user terminals, the system is convenient to install and maintain, and the positioning is stable, thereby providing accurate data sources for various location-based services.

Description of drawings

Figure 1 Service architecture when polarized wave indoor positioning is used independently

Fig. 2 Positioning flow chart using polarized wave positioning independently

Figure 3 The positioning flow chart of using polarized wave positioning in TD-SCDMA network

Detailed ways

As shown in Figure 1, the service architecture when the polarized wave indoor positioning system is used independently is described. The launch point and reference point for emitting circularly polarized waves are laid indoors. When the system is used independently, the launch point emits circularly polarized waves. The mobile terminal uses wireless communication methods such as Bluetooth or wireless LAN to control the launch point to emit different frequencies. The electromagnetic wave, by distinguishing the different frequencies of the electromagnetic wave, or the code division multiplexing of the single-frequency signal emitted by the transmitting point, etc. to distinguish each transmitting point; the mobile terminal is equipped with a polarized antenna that matches the transmitting point and ensures that it can be used anywhere in the room Receive signals transmitted by at least 3 transmitting points, and at the same time, the mobile terminal integrates location-based service LBS (Location Based Service) and communication functions; the reference point is equipped with polarized antennas and integrates communication functions; the location server integrates spatial database and signal strength database, At the same time, the communication function module, calculation module and its data feedback module are integrated.

When using polarized wave indoor positioning services in other network environments, such as using this system in communication networks such as GSM, CDMA, TD-SCDMA, LAN, etc., the basic requirements for the launch point and reference point are the same as the independent use of polarized wave The configuration is the same for indoor positioning; due to the limitation of the network, for example, the mobile terminal may only have the communication function in the TD-SCDMA network. Communicate with each other through RS-232 and other methods; the location server can be placed in a node in the network to facilitate communication with the mobile terminal.

As shown in Figure 2, it describes the positioning processing flow chart when the system is used alone for indoor positioning. First, the user terminal sends location request information to the LBS. The location request information includes service quality requirements such as response time, etc.; the LBS instructs the mobile terminal to send the information of the launch point and its reference point to the location server. These information include the launch point and The identification information of the reference point and its signal strength information, etc.; after receiving the above information, the location server undergoes power correction, and then uses the identification information of the emission point and the corrected signal strength information to search for the most matching sets of data in the database , the calculation module uses these sets of data to calculate the final positioning result, which is finally fed back to the LBS and displayed to the user.

As shown in Fig. 3, a flow chart of indoor positioning using polarized waves in other networks (such as TD-SCDMA) is described. The user sends a positioning request to the LBS of the auxiliary device; the polarized antenna on the auxiliary device obtains information such as the identification information and signal strength of the transmitting point and its reference point, and transmits this information to the mobile terminal through RS-232, wireless and other transmission methods ; The mobile terminal transmits the information to the base station through the Uu interface; the base station transmits the information to the CN (Core Network core network) through the Iu interface; the location server can be placed on a node of the CN, and the computing module in the location server is started, after matching and After calculation, the location information of the mobile terminal and the spatial data of the room where it is obtained are fed back to the auxiliary device, and the LBS of the auxiliary device feeds back its positioning result to the user.

When initializing the signal strength, the indoor environment is divided into small grids one by one. The size of the grid can be determined according to the accuracy required for positioning; the data of the signal strength of the emission point corresponding to the center of each grid is added to the spatial database middle.

The information stored in the database for each grid data is shown in Table 1 below:

Table 1 Database storage method

Grid ID Grid corresponds to spatial data Emission point ID + corresponding signal strength Emission point ID + corresponding signal strength Emission point ID + corresponding signal strength 001 ... 001-33dBm 002-52dBm 003-44dBm 002 ... 001-28dBm 002-39dBm 003-45dBm ... ... ... ... ...

After the network architecture layout and signal initialization measurement are completed, according to the positioning process described above, the mobile terminal will input the measured signal strength of at least 3 transmission points and the signal strength of the reference point into the location server; calculation initialization The ratio of the signal strength of the time reference point to the signal strength of the real-time reference point is multiplied by the signal strength values of the three real-time emission points to obtain the corrected signal strength of the emission point; then use the maximum likelihood matching Find several sets of data in the database that best match the signal strength of the corrected emission point, and input these data into the calculation module, and the calculation module assigns these sets of data to these groups according to the similarity between these sets of data and the actual measurement data. The corresponding weights of the data, and then calculate the weighted average of the position coordinates corresponding to these sets of data, and use it as the position coordinates of the mobile terminal to be requested, and output the position coordinates of the mobile terminal, and feed back to the user at the same time.

The invention adopts a circular polarization positioning method to provide accurate positioning for indoor mobile terminal users, thereby providing accurate data sources for various location-based services. The system can be used alone by users who only need indoor positioning services, or it can be based on other wireless communication networks and combined with outdoor positioning technology to achieve truly seamless positioning. It can be used in department stores, supermarkets, parking lots, etc.

Claims (4)

1. indoor terminal localization method based on circularly polarised wave, the integrated spatial database of location server, signal strength data storehouse, communication function module, computing module and data feedback module is characterized in that: at the launch point and the datum mark of indoor laying emission circularly polarised wave; Launch point sends circularly polarised wave; Be installed in mobile subscriber terminal or with auxiliary equipment that mobile subscriber terminal links to each other on poliarizing antenna receive circularly polarised wave when the even number secondary reflection signal strength signal intensity and it is sent into the signal strength data storehouse; System is to the signal strength signal intensity initialization; Mobile subscriber terminal sends Location Request to LBS; LBS indication mobile subscriber terminal sends to the circularly polarised wave of 3 launch points and datum mark thereof in the location server at least; Location server is proofreaied and correct the circularly polarised wave signal power of launch point according to the circularly polarised wave signal strength signal intensity of datum mark, and request signal intensity data storehouse, seeks matched data; Matched data in the computing module call signal intensity data storehouse is calculated the mobile subscriber terminal positional information; The data feedback module feeds back to mobile subscriber terminal with result of calculation.

2. indoor terminal localization method according to claim 1 is characterized in that: launch point emission circular polarization wave line of propagation is a forward.

3. indoor terminal localization method according to claim 1, it is characterized in that: the signal strength signal intensity initialization procedure comprises: the interior space is divided into some grids, measure the signal strength signal intensity of the corresponding launch point of grid element center, and it is added in the signal strength data storehouse.

4. indoor terminal localization method according to claim 3, it is characterized in that: sizing grid is divided according to positioning accuracy.

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